The accession of the Republic of Croatia to the European Union requires a regular review of policies, practices and procedures that affect ethical behaviour in the public sector. There are increasing expectations from public that governments should foster and sustain higher standard of integrity in the public service. In this context, joining the EU many states recognized ethical cultures as a crucial priority in general. It is considered to be a vital component for maintaining the confidence of society and politicians in the public sector. Responsibility of management in public sector is to establish the ethics-based organizational culture through ethical infrastructure that promotes ethical values in decision-making, work processes and operations. In transitional economy the responsibility is particularly stressed. After fast replacement of the old system, the change goes much slower and often much longer retain the remains of replaced and incompletely destroyed social system. Communism and collectivistically- oriented society did leave a unique legacy by creating a peculiar cultural syndrome at the enterprise level generating a challenge for doing business there. This article examines the results of a study conducted in public sector units in Croatia. The aim of the study was to examine and describe the efficiency of ethical organisational culture in Croatian public sector. The construct of efficiency was measured by a consideration of three areas: legal framework, institutional setting and ethical infrastructure. The results indicate that most public sector units are in the early stages of development. It is established a basic framework for the ethical conduct of civil servants in the public administration, but the government bodies did not take specific actions to motivate and encourage civil servants to adopt certain ethical principles and values and to implement them in daily operation.